The present disclosure described herein relates to a semiconductor memory, and more particularly, to a solid state drive including a nonvolatile memory, a random access memory, and a memory controller.
A storage device is a device that stores data according to a control of a host device, such as a computer, a smart phone, a smart pad, and so on. The storage device may contain a device which stores data on a magnetic disk such as a Hard Disk Drive, or a device which stores data on a semiconductor memory, in particular on a nonvolatile memory, such as a Solid State Drive (SSD) or a memory card.
A nonvolatile memory may be a Read Only Memory (ROM), a Programmable ROM (PROM), an Electrically Programmable ROM (EPROM), an Electrically Erasable and Programmable ROM EEPROM), a flash memory, a Phase-change RAM (PRAM), a Magnetic RAM (MRAM), a Resistive RAM (RRAM), or a Ferroelectric RAM (FRAM).
Advancements in semiconductor fabrication technology have enabled a continued increase in the capacity of a solid state drive. As example, increase capacity may be accomplished through overlapping of semiconductor memory chips and increased integration of a semiconductor memory chip.
Generally, however, an increase in the capacity of the solid state drive hinders the reliability of a storage device. For example, the higher the number of semiconductor chips that are overlapped, the greater are certain resistance components of the overlapped chips. A toggle speed of a channel that is used to communicate with the semiconductor chips is hindered due to the increase in resistance components, thereby resulting in an increase in skew.